| Message ID | 20180802144834.520904-2-eblake@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | NBD fixes for unaligned images | expand |
02.08.2018 17:48, Eric Blake wrote: > The next patch needs access to a device's minimum permitted > alignment, since NBD wants to advertise this to clients. Add > an accessor function, borrowing from blk_get_max_transfer() > for accessing a backend's block limits. > > Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h index 830d873f24f..20f8bbbce37 100644 --- a/include/sysemu/block-backend.h +++ b/include/sysemu/block-backend.h @@ -176,6 +176,7 @@ bool blk_is_available(BlockBackend *blk); void blk_lock_medium(BlockBackend *blk, bool locked); void blk_eject(BlockBackend *blk, bool eject_flag); int blk_get_flags(BlockBackend *blk); +uint32_t blk_get_request_alignment(BlockBackend *blk); uint32_t blk_get_max_transfer(BlockBackend *blk); int blk_get_max_iov(BlockBackend *blk); void blk_set_guest_block_size(BlockBackend *blk, int align); diff --git a/block/block-backend.c b/block/block-backend.c index f2f75a977d7..fb8c827d117 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -1798,6 +1798,13 @@ int blk_get_flags(BlockBackend *blk) } } +/* Returns the minimum request alignment, in bytes; guaranteed nonzero */ +uint32_t blk_get_request_alignment(BlockBackend *blk) +{ + BlockDriverState *bs = blk_bs(blk); + return bs ? bs->bl.request_alignment : BDRV_SECTOR_SIZE; +} + /* Returns the maximum transfer length, in bytes; guaranteed nonzero */ uint32_t blk_get_max_transfer(BlockBackend *blk) {
The next patch needs access to a device's minimum permitted alignment, since NBD wants to advertise this to clients. Add an accessor function, borrowing from blk_get_max_transfer() for accessing a backend's block limits. Signed-off-by: Eric Blake <eblake@redhat.com> --- include/sysemu/block-backend.h | 1 + block/block-backend.c | 7 +++++++ 2 files changed, 8 insertions(+)